EP0446497B1 - Continuously variable transmission - Google Patents

Continuously variable transmission Download PDF

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Publication number
EP0446497B1
EP0446497B1 EP90203453A EP90203453A EP0446497B1 EP 0446497 B1 EP0446497 B1 EP 0446497B1 EP 90203453 A EP90203453 A EP 90203453A EP 90203453 A EP90203453 A EP 90203453A EP 0446497 B1 EP0446497 B1 EP 0446497B1
Authority
EP
European Patent Office
Prior art keywords
continuously variable
variable transmission
transmission according
friction plate
slip
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP90203453A
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German (de)
French (fr)
Other versions
EP0446497A1 (en
Inventor
Sebastiaan W.M. Van Vuuren
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Bosch Transmission Technology BV
Original Assignee
Van Doornes Transmissie BV
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
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Publication of EP0446497A1 publication Critical patent/EP0446497A1/en
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Expired - Lifetime legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H9/00—Gearings for conveying rotary motion with variable gear ratio, or for reversing rotary motion, by endless flexible members
    • F16H9/02—Gearings for conveying rotary motion with variable gear ratio, or for reversing rotary motion, by endless flexible members without members having orbital motion
    • F16H9/04—Gearings for conveying rotary motion with variable gear ratio, or for reversing rotary motion, by endless flexible members without members having orbital motion using belts, V-belts, or ropes
    • F16H9/12—Gearings for conveying rotary motion with variable gear ratio, or for reversing rotary motion, by endless flexible members without members having orbital motion using belts, V-belts, or ropes engaging a pulley built-up out of relatively axially-adjustable parts in which the belt engages the opposite flanges of the pulley directly without interposed belt-supporting members
    • F16H9/16—Gearings for conveying rotary motion with variable gear ratio, or for reversing rotary motion, by endless flexible members without members having orbital motion using belts, V-belts, or ropes engaging a pulley built-up out of relatively axially-adjustable parts in which the belt engages the opposite flanges of the pulley directly without interposed belt-supporting members using two pulleys, both built-up out of adjustable conical parts
    • F16H9/18—Gearings for conveying rotary motion with variable gear ratio, or for reversing rotary motion, by endless flexible members without members having orbital motion using belts, V-belts, or ropes engaging a pulley built-up out of relatively axially-adjustable parts in which the belt engages the opposite flanges of the pulley directly without interposed belt-supporting members using two pulleys, both built-up out of adjustable conical parts only one flange of each pulley being adjustable
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H61/00—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing
    • F16H61/66—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing specially adapted for continuously variable gearings
    • F16H2061/6604—Special control features generally applicable to continuously variable gearings
    • F16H2061/6618—Protecting CVTs against overload by limiting clutch capacity, e.g. torque fuse
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H37/00—Combinations of mechanical gearings, not provided for in groups F16H1/00 - F16H35/00
    • F16H37/02—Combinations of mechanical gearings, not provided for in groups F16H1/00 - F16H35/00 comprising essentially only toothed or friction gearings
    • F16H37/021—Combinations of mechanical gearings, not provided for in groups F16H1/00 - F16H35/00 comprising essentially only toothed or friction gearings toothed gearing combined with continuous variable friction gearing
    • F16H37/022—Combinations of mechanical gearings, not provided for in groups F16H1/00 - F16H35/00 comprising essentially only toothed or friction gearings toothed gearing combined with continuous variable friction gearing the toothed gearing having orbital motion
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H61/00—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing
    • F16H61/66—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing specially adapted for continuously variable gearings
    • F16H61/662—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing specially adapted for continuously variable gearings with endless flexible members
    • F16H61/66272—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing specially adapted for continuously variable gearings with endless flexible members characterised by means for controlling the torque transmitting capability of the gearing

Definitions

  • the invention relates to a Continuously variable transmission at least provided with a primary pulley fixed to a primary shaft, a secondary pulley fixed to a secondary shaft, an endless transmission element located between the primary and secondary pulleys to transmit torque therebetween, wherein friction slip preventing means are arranged such in the torque path of the transmission that in all circumstances the maximum torque to be transmitted through the slip preventing means in those cases is smaller than the slip torque of the endless transmission element under the same conditions.
  • Such a generic continuously variable transmission is known from US-A-4 606 446.
  • the slip preventing means of this known transmission comprises a magnetic particle clutch. During operation an electrical current is fed to a coil of the clutch which generates heat in the clutch. Only when a vehicle comprising the known transmission runs at low speed this clutch is disengaged. This heat production has a disadvantageous effect on the efficiency of the transmission
  • slip prevention means slip of the endless transmission element and of the pulley is prevented. Also the pinching force of the pulleys on the endless transmission element can be decreased whereby the efficiency of the transmission is increased.
  • a continuously variable transmission having a mechanical friction clutch is known per se from EP-A 0 109 001.
  • this known clutch does not function as a slip preventing means. Therefore a disadvantage of this known transmission is that the endless transmission element can slip between the pulleys when the torques to be transmitted, for instance transmission shocks, become too large. This slip is undesirable in view of wear and economy.
  • the slip can to some extent be met by increasing the pinching force of one or both pulleys on the endless transmission element. An increase of the pinching force however has a disadvantageous effect on the efficiency of the transmission.
  • the slip prevention means can to this end be provided with slip elements which start to slip at a lower torque than that of the endless transmission element. In this case slip also occurs but not at an undesirable place and not in an uncontrollable way.
  • the slip means are controllable so that dependent on the circumstances, for instance dependent on the torque to be transmitted, the magnitude of the slip can be adjusted.
  • the slip prevention means preferably also are provided with centrifugal compensation means.
  • the slip prevention means in the form of said friction plate-type clutch means advantageously is a part of the forward coupling of a clutch which usually is present in a forward/rearward/neutral clutch unit.
  • the magnitude of the slip is in that case preferably adjustable for instance by means of a fluid pressure in dependance of the circumstances such as the torque to be transmitted.
  • FIGS 1, 2 and 3 schematically a continuously variable tranmission is represented provided with an ingoing shaft 1 which is for instance driven by an internal combustion engine.
  • the ingoing shaft 1 drives a primary shaft 2 bearing a primary pulley consisting of a coaxially displaceable disc 4 and a stationary disc 3.
  • a secondary shaft 5 bears a secondary pulley including a coaxially displaceable disc 6 and a stationary disc 7.
  • an endless transmission element (8) is provided between the primary (3, 4) and the secondary (6, 7) pulley.
  • the transmission ratio of the transmission can be continuously adjusted by moving the axially displaceable pulley discs 4, 6 which results in an adjustment of the radial position of the endless transmission element.
  • the continuously variable transmission is provided with slip preventing means with adjustable slip elements in the form of a controllable clutch 10.
  • the clutch is provided with blades 11 which may be compressed by a plunger 12 to a greater or lesser extent in order to transmit a larger or smaller torque from the ingoing shaft 1 to the secondary shaft 2 by the friction contact there between.
  • the fluid pressure in cylinder 13 is thereby adjusted such that the plunger 12 compresses the blades 11 of the clutch 10 to such an extent that the maximum torque to be transmitted by clutch 10 is always smaller and preferably just smaller than the torque where the endless transmission element 8 would in these cases slip in the pulleys.
  • the clutch has to this end such a construction that under all circumstances the clutch 10 will slip at an earlier moment than the endless transmission element 8.
  • the continuously variable transmission according to figure 2 again has a clutch 20 comprising blades 21, a piston 22 and a cylinder 23.
  • the centrifugal pressure in cylinder 23 however is now compensated by a compensation chamber 24 on the side of the piston 22 facing the cylinder 23.
  • the chamber 24 is in this case supplied with the fluid through orifice 25 in the piston 22. Fluid from the chamber 24 flows off through the opening 26.
  • the pressure builds-up through the centrifugal action on both sides of the piston 22 are of the same magnitude and thus compensate eachother.
  • the value of the compression by the piston 22 of the blades 21 is thereby explicitely determined by the adjusted static pressure in the cylinder 23.
  • the slip of the clutch is thereby optimally adjusted and also the slip prevention of the endless transmission element is at an optimum.
  • the orifice 25 in the piston 22 may be provided with a filter, a sieve or other means to prevent clogging of the element 25 by deposit of impurities present in the fluid.
  • Continuously variable transmissions which are used in vehicles also comprise in many cases a clutch unit for forward/rearward/neutral, enabling the vehicle to be given at will a forward or rearward direction or to be kept in a neutral position.
  • Figure 3 shows such a forward/rearward/neutral clutch unit in the form of a planetary gearset 30 comprising a ringwheel 31, planetwheels 32 and a sun wheel 33, a rearward clutch 34 and a forward clutch 20.
  • the clutch 20 according to figure 2 is thereby integrated as a forward clutch 20 with the forward/rearward/neutral clutch unit of the transmission.
  • slip prevention means in the embodiments according to figures 1-3 are located in front of the primary pulley they can according to the invention without objection also be placed behind the secondary pulley, seen in the direction of driving, because the increased torques, for instance caused by coupling shocks from the engine or from the road can be absorbed independently of the inposition without the transmission element 8 being caused.
  • the lock-up can for instance be controlled in a pulsating way such that a controlled continuous slip will occur. As the lock-up (or the bridging clutch) slips continuously the lock-up will slip still more by a coupling shock but slip of the endless transmission element between the pulleys will be prevented.

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Transmissions By Endless Flexible Members (AREA)
  • Control Of Transmission Device (AREA)

Description

  • The invention relates to a Continuously variable transmission at least provided with a primary pulley fixed to a primary shaft, a secondary pulley fixed to a secondary shaft, an endless transmission element located between the primary and secondary pulleys to transmit torque therebetween, wherein friction slip preventing means are arranged such in the torque path of the transmission that in all circumstances the maximum torque to be transmitted through the slip preventing means in those cases is smaller than the slip torque of the endless transmission element under the same conditions.
  • Such a generic continuously variable transmission is known from US-A-4 606 446. The slip preventing means of this known transmission comprises a magnetic particle clutch. During operation an electrical current is fed to a coil of the clutch which generates heat in the clutch. Only when a vehicle comprising the known transmission runs at low speed this clutch is disengaged. This heat production has a disadvantageous effect on the efficiency of the transmission
  • It is an object of the present invention to further develop the generic transmission and to this end to provide a continuously variable transmission which is characterized in that said slip preventing means comprise friction plate-type clutch means.
  • By the use of the slip prevention means slip of the endless transmission element and of the pulley is prevented. Also the pinching force of the pulleys on the endless transmission element can be decreased whereby the efficiency of the transmission is increased.
  • A continuously variable transmission having a mechanical friction clutch is known per se from EP-A 0 109 001. However this known clutch does not function as a slip preventing means. Therefore a disadvantage of this known transmission is that the endless transmission element can slip between the pulleys when the torques to be transmitted, for instance transmission shocks, become too large. This slip is undesirable in view of wear and economy. The slip can to some extent be met by increasing the pinching force of one or both pulleys on the endless transmission element. An increase of the pinching force however has a disadvantageous effect on the efficiency of the transmission.
  • The slip prevention means can to this end be provided with slip elements which start to slip at a lower torque than that of the endless transmission element. In this case slip also occurs but not at an undesirable place and not in an uncontrollable way. Preferably the slip means are controllable so that dependent on the circumstances, for instance dependent on the torque to be transmitted, the magnitude of the slip can be adjusted. To prevent the influence of a centrifugal action the slip prevention means preferably also are provided with centrifugal compensation means.
  • According to a further development of the invention the slip prevention means in the form of said friction plate-type clutch means advantageously is a part of the forward coupling of a clutch which usually is present in a forward/rearward/neutral clutch unit. The magnitude of the slip is in that case preferably adjustable for instance by means of a fluid pressure in dependance of the circumstances such as the torque to be transmitted.
  • The invention will be explained in more detail by some examples of different embodiments in connection with a drawing. The drawing shows in:
    • figure 1
    schematically a continuously variable transmission provided with slip prevention means including an adjustable clutch;
    figure 2
    schematically a continuously variable transmission provided with slip prevention means including a clutch together with centrifugal compensation means; and
    figure 3
    the continuously variable transmission according to figure 2 wherein the clutch is part of a forward/rearward/neutral unit.
  • In figures 1, 2 and 3 schematically a continuously variable tranmission is represented provided with an ingoing shaft 1 which is for instance driven by an internal combustion engine. The ingoing shaft 1 drives a primary shaft 2 bearing a primary pulley consisting of a coaxially displaceable disc 4 and a stationary disc 3. A secondary shaft 5 bears a secondary pulley including a coaxially displaceable disc 6 and a stationary disc 7. Between the primary (3, 4) and the secondary (6, 7) pulley an endless transmission element (8) is provided. In a manner which is known in itself the transmission ratio of the transmission can be continuously adjusted by moving the axially displaceable pulley discs 4, 6 which results in an adjustment of the radial position of the endless transmission element.
  • When too large torques are to be transmitted there is a possibility that the friction forces between the primary and the secondary pulley on one side and the endless transmission element on the other side are insufficient to transmit these torques. As a consequence the endless transmission element slips between the pulleys. This is undesirable in view of the wear which ensures. It is possible to increase the friction between the pulleys and the endless transmission element 8 by increasing the pinching force on the endless transmission element in one or both pulleys. From the point of efficiency considerations this however is undesirable. When for instance the pinching force is hydraulically transmitted to the pulleys as described in EP-A-109001 such an increase of the pinching force requires a larger pump having a larger flow and/or a higher pressure which influences the efficiency of the transmission in a disadvantageous way. A larger pump is moreover expensive and requires more space for building in.
  • In figure 1 the continuously variable transmission is provided with slip preventing means with adjustable slip elements in the form of a controllable clutch 10. The clutch is provided with blades 11 which may be compressed by a plunger 12 to a greater or lesser extent in order to transmit a larger or smaller torque from the ingoing shaft 1 to the secondary shaft 2 by the friction contact there between. The fluid pressure in cylinder 13 is thereby adjusted such that the plunger 12 compresses the blades 11 of the clutch 10 to such an extent that the maximum torque to be transmitted by clutch 10 is always smaller and preferably just smaller than the torque where the endless transmission element 8 would in these cases slip in the pulleys. The clutch has to this end such a construction that under all circumstances the clutch 10 will slip at an earlier moment than the endless transmission element 8. It is true that then the slip occurs at the blades 11 but this is acceptable because generally the blades 11 and the clutch 10 can be adapted thereto. The pinching force of the pulleys on the endless transmission element need moreover not to be overdimensioned because the slip prevention means take over the safety function thereof. In general the efficiency of the transmission is greatly improved.
  • As in the cylinder 13 apart from the static pressure a pressure build-up takes place by the centrifugal action of the fluid in the rotating cylinder 13 the pressure adjustment and the slip prevention connected therewith will be improved but is not yet at its optimum. In the embodiment of the invention according to figure 2 this centrifugal action is avoided resulting in an optimal pressure adjustment and connnected therewith an optimal slip prevention
  • The continuously variable transmission according to figure 2 again has a clutch 20 comprising blades 21, a piston 22 and a cylinder 23. The centrifugal pressure in cylinder 23 however is now compensated by a compensation chamber 24 on the side of the piston 22 facing the cylinder 23. The chamber 24 is in this case supplied with the fluid through orifice 25 in the piston 22. Fluid from the chamber 24 flows off through the opening 26. In view of the fact that the fluid in the chambers 24 rotates with the same speed as in cylinder 23 the pressure builds-up through the centrifugal action on both sides of the piston 22 are of the same magnitude and thus compensate eachother. The value of the compression by the piston 22 of the blades 21 is thereby explicitely determined by the adjusted static pressure in the cylinder 23. The slip of the clutch is thereby optimally adjusted and also the slip prevention of the endless transmission element is at an optimum. As the case may be the orifice 25 in the piston 22 may be provided with a filter, a sieve or other means to prevent clogging of the element 25 by deposit of impurities present in the fluid.
  • Continuously variable transmissions which are used in vehicles also comprise in many cases a clutch unit for forward/rearward/neutral, enabling the vehicle to be given at will a forward or rearward direction or to be kept in a neutral position. Figure 3 shows such a forward/rearward/neutral clutch unit in the form of a planetary gearset 30 comprising a ringwheel 31, planetwheels 32 and a sun wheel 33, a rearward clutch 34 and a forward clutch 20. The clutch 20 according to figure 2 is thereby integrated as a forward clutch 20 with the forward/rearward/neutral clutch unit of the transmission.
  • Although the slip prevention means in the embodiments according to figures 1-3 are located in front of the primary pulley they can according to the invention without objection also be placed behind the secondary pulley, seen in the direction of driving, because the increased torques, for instance caused by coupling shocks from the engine or from the road can be absorbed independently of the inposition without the transmission element 8 being caused.
  • It will be apparent that the invention is not limited to the embodiments shown but that within the scope of the invention many alternatives are possible and are thus considered to be within the scope of the invention. So for instance in case the transmission is provided with a torque conventer the bridging clutch of the lock-up means of said torque converter may be integrated in the slip preventing means.
  • The lock-up can for instance be controlled in a pulsating way such that a controlled continuous slip will occur. As the lock-up (or the bridging clutch) slips continuously the lock-up will slip still more by a coupling shock but slip of the endless transmission element between the pulleys will be prevented.

Claims (11)

  1. Continuously variable transmission at least provided with a primary pulley (3, 4) fixed to a primary shaft (1), a secondary pulley (6, 7) fixed to a secondary shaft (5), an endless transmission element (8) located between the primary and secondary pulleys to transmit torque therebetween, wherein friction slip preventing means are arranged such in the torque path of the transmission that in all circumstances the maximum torque to be transmitted through the slip preventing means in those cases is smaller than the slip torque of the endless transmission element under the same conditions, characterized in that said friction slip preventing means comprise friction plate-type clutch means.
  2. Continuously variable transmission according to Claim 1, wherein said friction plate-type clutch means are adjustable.
  3. Continuously variable transmission according to claim 2, wherein a centrifugal compensation means is provided.
  4. Continuously variable transmission according to claim 1 or 2, wherein said friction plate-type clutch means are adjustable by means of a fluid.
  5. Continuously variable transmission according to claim 4, wherein said friction plate-type clutch means are adjustable by means of a shiftable piston unit (12; 22) located in a cylinder (13; 23).
  6. Continuously variable transmission according to claim 5, wherein additionally a compensation chamber (24) is provided to compensate the centrifugal pressure acting on the piston (22).
  7. Continuously variable transmission according to claim 6, wherein the compensation chamber (24) is supplied with a fluid by means of an orifice (25) located in the piston (22).
  8. Continuously variable transmission according to claim 7, wherein said orifice (25) is provided with means to prevent clogging of said orifice.
  9. Continuously variable transmission according to one of the preceding claims, wherein said friction plate-type clutch means are the forward clutch of a coupling unit for forward or rearward drive-mode or a neutral mode.
  10. Continuously variable transmission according to one or more of the claims 1 to 9, wherein said friction plate-type clutch means are located in front of the primary pulley seen in the direction of driving.
  11. Continuously variable transmission according to one or more of the claims 1 to 9, wherein said friction plate-type clutch means are located behind the secondary pulley seen in the direction of driving.
EP90203453A 1990-03-15 1990-12-20 Continuously variable transmission Expired - Lifetime EP0446497B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
NL9000589 1990-03-15
NL9000589A NL9000589A (en) 1990-03-15 1990-03-15 CONTINUOUSLY VARIABLE TRANSMISSION.

Publications (2)

Publication Number Publication Date
EP0446497A1 EP0446497A1 (en) 1991-09-18
EP0446497B1 true EP0446497B1 (en) 1994-09-21

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EP90203453A Expired - Lifetime EP0446497B1 (en) 1990-03-15 1990-12-20 Continuously variable transmission

Country Status (5)

Country Link
US (1) US5098345A (en)
EP (1) EP0446497B1 (en)
JP (1) JP3271993B2 (en)
DE (1) DE69012792T2 (en)
NL (1) NL9000589A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10222664A1 (en) * 2002-05-22 2003-12-18 Bosch Gmbh Robert Slip control method on a clutch associated with an automatic gearbox
WO2015106350A1 (en) * 2014-01-16 2015-07-23 Transmission Cvtcorp Inc. Slip control method and arrangement for a driveline including a continuously variable transmission

Families Citing this family (29)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4324810A1 (en) * 1993-07-23 1995-01-26 Zahnradfabrik Friedrichshafen Control procedure for a continuously variable belt transmission
GB2319817B (en) * 1994-02-23 1998-10-07 Luk Getriebe Systeme Gmbh Control method for a torque transfer system and torque transfer system for carrying out the control method
DE19504847B4 (en) * 1994-02-23 2006-04-27 Luk Gs Verwaltungs Kg Monitoring method for a torque transmission system of a motor vehicle
DE4417346A1 (en) * 1994-05-18 1995-11-30 Telefunken Microelectron Method for adjusting the preload force for the transmission element of a continuously variable transmission
DE19522674A1 (en) * 1995-06-22 1997-01-02 Bosch Gmbh Robert Hydraulic control for changing the hydraulic oil pressure in the hydraulic conical pulley axial adjustment of a continuously variable belt transmission to vary the clamping force
DE19603239B4 (en) * 1996-01-30 2005-07-14 Bayerische Motoren Werke Ag Method for increasing the rotational speed or the torque of a vehicle engine
NL1002245C2 (en) * 1996-02-05 1997-08-07 Doornes Transmissie Bv Continuously variable transmission.
DE19638277A1 (en) * 1996-09-19 1998-03-26 Bosch Gmbh Robert Device and method for operating a belt transmission
DE19712451A1 (en) 1997-03-25 1998-10-01 Bosch Gmbh Robert Device and method for controlling a CVT in a motor vehicle
DE19712713A1 (en) * 1997-03-26 1998-10-01 Bosch Gmbh Robert Device and method for controlling a CVT in a motor vehicle
NL1006684C2 (en) * 1997-07-29 1999-02-01 Doornes Transmissie Bv Drive device provided with torque limiting means.
US5937711A (en) * 1998-03-19 1999-08-17 Ford Global Technologies, Inc. All wheel drive continuously variable transmission having dual mode operation
US6093125A (en) * 1998-03-19 2000-07-25 Ford Global Technologies, Inc. All wheel drive continuously variable transmission having dual mode operation
US5941789A (en) * 1998-03-19 1999-08-24 Ford Global Technologies, Inc. All wheel drive continuously variable transmission having dual mode operation
US5916053A (en) * 1998-03-19 1999-06-29 Ford Global Technologies, Inc. Dual mode operation continuously variable transmission having creeper low and reverse gears
US5888161A (en) * 1998-03-19 1999-03-30 Ford Global Technologies, Inc. All wheel drive continuously variable transmission having dual mode operation
US6106428A (en) * 1998-03-23 2000-08-22 Ford Global Technologies, Inc. Compact dual mode continually variable transmission
US5950488A (en) * 1998-04-13 1999-09-14 Abdallah; Abdalla Aref Positive engagement continuously variable transmission
EP1069331B1 (en) 1999-07-06 2002-05-08 Van Doorne's Transmissie B.V. Method for controlling a continuously variable transmission having a continuously slipping clutch
JP3571607B2 (en) * 2000-03-27 2004-09-29 本田技研工業株式会社 Belt type continuously variable transmission
JP2005502008A (en) * 2001-08-31 2005-01-20 トロトラック・（ディベロップメント）・リミテッド Continuously variable transmission and operation method thereof
JP2003120804A (en) * 2001-10-09 2003-04-23 Toyota Motor Corp Controller for driving mechanism including continuously variable transmission
US6974009B2 (en) 2002-02-04 2005-12-13 Toyota Jidosha Kabushiki Kaisha Control apparatus for power train including continuously variable transmission
TWI220022B (en) * 2002-05-27 2004-08-01 Richtek Technology Corp Current sensing apparatus and method
US20050272540A1 (en) * 2004-05-03 2005-12-08 Starkey John M Coaxial electrical actuator for continuously variable transmission
US8118707B2 (en) 2005-12-28 2012-02-21 Robert Bosch Gmbh Method for controlling a belt-type continuously variable transmission and a friction clutch in a vehicular drive line
FR2905409B1 (en) * 2006-08-31 2012-04-27 Peugeot Citroen Automobiles Sa DEVICE FOR DRIVING A CENTRIFUGAL COMPRESSOR OF SUPERIMUMENTATION OF AN INTERNAL COMBUSTION ENGINE IN PARTICULAR OF A MOTOR VEHICLE
US8762018B2 (en) * 2008-05-01 2014-06-24 Allison Transmission, Inc. Method and apparatus for clutch pressure control
JP5511264B2 (en) * 2009-08-24 2014-06-04 ダイハツ工業株式会社 Idle stop vehicle starting clutch control device

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE421084B (en) * 1981-01-29 1981-11-23 Ffv Industriprodukter Ab SEKERHETSSLIRKOPPLING
IT1144396B (en) * 1981-07-17 1986-10-29 Fiat Auto Spa EQUIPMENT FOR THE CONTROL OF A CONTINUOUS AUTOMATIC TRANSMISSION OF A VEHICLE
DE3241789C2 (en) * 1982-11-11 1985-08-08 Ford-Werke AG, 5000 Köln Gear unit for vehicles, in particular for front-wheel drive vehicles
US4541821A (en) * 1982-11-27 1985-09-17 Aisin-Warner Limited V-belt type stepless transmission
JPS59190522A (en) * 1983-04-08 1984-10-29 Toyota Motor Corp Controller of magnetic powder system solenoid clutch for vehicle
US4909776A (en) * 1987-08-28 1990-03-20 Aisin Aw Co., Ltd. Continuously variable transmission

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
Handbook of power drives, 2nd edition, pages 196/197 *
Kupplungs-Atlas, Bauarten und Auslegung von Kupplungen und Bremsen, 4. Auflage, Seiten 184/185 *

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10222664A1 (en) * 2002-05-22 2003-12-18 Bosch Gmbh Robert Slip control method on a clutch associated with an automatic gearbox
DE10222664B4 (en) * 2002-05-22 2004-04-29 Robert Bosch Gmbh Method for controlling the operating mode of an automatic transmission stage and a clutch working together with the automatic transmission stage
WO2015106350A1 (en) * 2014-01-16 2015-07-23 Transmission Cvtcorp Inc. Slip control method and arrangement for a driveline including a continuously variable transmission
US10308255B2 (en) 2014-01-16 2019-06-04 Transmission Cvtcorp Inc. Slip control method and arrangement for a driveline including a continuously variable transmission

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Publication number Publication date
EP0446497A1 (en) 1991-09-18
DE69012792T2 (en) 1995-02-02
JPH04228960A (en) 1992-08-18
NL9000589A (en) 1991-10-01
JP3271993B2 (en) 2002-04-08
US5098345A (en) 1992-03-24
DE69012792D1 (en) 1994-10-27

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